Low drag low noise devices using jet flow control

ABSTRACT

Low drag low noise devices are described herein that use passive jet flow control to reduce the drag and noise created by motor vehicles (e.g., motor vehicle side view mirrors) while the motor vehicles travel through a fluid. The low drag low noise devices described herein comprise a lengthwise axis, an outer body, and an inner body. The outer body and the inner body cooperatively define a channel through which fluid can pass during use.

PRIORITY/CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.61/976,204, filed Apr. 7, 2014, and is a continuation-in-part of U.S.Nonprovisional application Ser. No. 14/180,406, filed Feb. 14, 2014,which is a continuation-in-part of International Application No.PCT/US2013/053191, filed Aug. 1, 2013, which claims the benefit ofProvisional Application No. 61/765,219, filed Feb. 15, 2013. The entirecontents of each of these related applications are hereby incorporatedinto this disclosure by reference.

FIELD

The disclosure relates generally to low drag low noise devices. Morespecifically, the disclosure relates to various embodiments of low draglow noise devices that use passive jet flow control to reduce the levelof both drag and noise. The low drag low noise devices described hereincan be used to reduce the drag and noise on any suitable motor vehicle(e.g., automobile, car, truck, motorcycle, boat, locomotive, aircraft,airplane, projectile) or device, such as an external side view mirrorattached to a motor vehicle (e.g., automobile, car, truck, motorcycle,boat, locomotive, aircraft, airplane, projectile).

BACKGROUND

Motor vehicles, such as automobiles, cars, trucks, motorcycles, boats,locomotives, aircrafts, airplanes, projectiles, and the like, haveemerged as the dominant form of human transportation in the modern worldand are capable of transporting a human operator and passengers overgreat distances at great speeds relative to older forms oftransportation. The speed at which a motor vehicle can travel can varybased on a number of factors, such as the type of motor vehicle beingused, the material on which the motor vehicle is travelling, and thefluid through which the motor vehicle is travelling. In some cases, thespeed at which a motor vehicle can travel can vary and range frombetween ten miles an hour up to above four hundred miles an hour. Thesespeeds are enough to cause significant aerodynamic drag on the motorvehicle as it travels through a fluid. As a result, most motor vehiclesare aerodynamically designed and use the concepts of fluid dynamics suchthat the fluid through which the car is travelling (e.g., air) can bedirected over and around the body of the motor vehicle to achieve areduction in drag relative to motor vehicles that are notaerodynamically designed. In addition, by aerodynamically designing themotor vehicle, the performance and gas mileage of the motor vehicle canbe increased.

A significant portion of the drag forces applied to a motor vehicleduring travel are a result of the external side view mirrors thatgenerally protrude from the vehicle cabin. Each of FIGS. 1, 2, and 3,illustrate a common shape of a side view mirror. During travel, each ofthese mirrors is exposed to the oncoming flow of fluid, which increasesthe drag applied to the motor vehicle and reduces fuel efficiency. Thedrag percentage created by the external side view mirrors is greater forsmaller and lighter vehicles (e.g., electric cars, Formula 1, Smart,Mini Cooper), which have an overall less capture area (e.g., the maximumcross-sectional area of the vehicle perpendicular to the vehicle movingdirection) than larger motor vehicles traveling at the same speed.Therefore, drag forces can more readily decelerate smaller vehicles.

Apart from drag force, another product of a motor vehicle travellingthrough a fluid, such as air, is noise. Most noise created during traveland heard by an operator when operating the motor vehicle does not comefrom the engine. Instead, the noise is a product of the flow of fluidaround the motor vehicle. In particular, the side view mirrors are oneof the major sources of noise that the operator and any other occupantsof the vehicle hear during travel.

Drag and noise are a direct result of the flow conditions created by theshape of the side view mirrors. For example, flow conditions such ashigh turbulent pressure fluctuations and vortex shedding create drag,noise, and a low base pressure behind the flat rear surface of themirror as a motor vehicle travels through a fluid. In addition, theseflow conditions create a condition referred to as base flow. An exampleof how vortex shedding is created by using a common side view mirror canbe seen in FIG. 4, which illustrates the side view mirror travellingthrough air that is illustrated as streamlines travelling around theside view mirror. As illustrated, the flow conditions are a result ofthe side view mirror having a streamlined front surface and abruptlyterminating in a flat back (e.g., the mirror). These conditions are alsocreated behind the flat, or substantially flat, surfaces of the motorvehicle, such as the rear end of the motor vehicle.

The present disclosure provides a low noise low drag device that usesjet flow control to reduce the effects of base flow vortex shedding, andthereby reduce the noise and drag. The present disclosure achieves thisreduction in drag and noise by manipulating the flow of fluid (e.g.,air) around the low drag low noise device to create directed jet(s) ofair around the flat, or substantially flat, surface on the rear of thedevice (e.g., the mirror of a side view mirror) or the motor vehicle(e.g., rear end) creating a virtual trailing edge, or boat-tail, thatreduces or removes vortex shedding. Thus, the jet(s) produced by the lowdrag low noise devices described herein act to counter base flow andreduce drag and noise.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top view of a portion of a motor vehicle with an attachedexternal side view mirror.

FIG. 2 is a side view of a portion of another motor vehicle with anattached external side view mirror.

FIG. 3 is a side view of a portion of another motor vehicle with anattached external side view mirror.

FIG. 4 is a side view of a motor vehicle external side view mirrorsubjected to a flow field. FIG. 4 illustrates streamlines of the flowfield depicting how the motor vehicle external side view mirror causesvortex shedding.

FIG. 5 is a front perspective view of a low drag low noise device.

FIG. 6 is a front view of the low drag low noise device illustrated inFIG. 5.

FIG. 7 is a right side view of the low drag low noise device illustratedin FIG. 5.

FIG. 8 is a rear view of the low drag low noise device illustrated inFIG. 5.

FIG. 9 is a wireframe front perspective view of the low drag low noisedevice illustrated in FIG. 5.

FIG. 10 is a sectional view of the low drag low noise device illustratedin FIG. 6, taken along line 10-10. FIG. 10 depicts the low drag lownoise device subjected to a flow field and how fluid flows through thelow drag low noise device.

FIG. 11 is a sectional view of the low drag low noise device illustratedin FIG. 6, taken along line 11-11. FIG. 11 depicts the low drag lownoise device subjected to a flow field and how fluid flows through thelow drag low noise device.

FIG. 11A is a magnified view of area 11A illustrated in FIG. 11.

FIG. 12 is a front perspective view of another low drag low noisedevice.

FIG. 13 is a front view of the low drag low noise device illustrated inFIG. 12.

FIG. 14 is a right side view of the low drag low noise deviceillustrated in FIG. 12.

FIG. 15 is a rear view of the low drag low noise device illustrated inFIG. 12.

FIG. 16 is a wireframe front perspective view of low drag low noisedevice illustrated in FIG. 12.

FIG. 17 is a sectional view of the low drag low noise device illustratedin FIG. 13, taken along line 17-17. FIG. 17 depicts the low drag lownoise device subjected to a flow field and how fluid flows through thelow drag low noise device.

FIG. 18 is a sectional view of the low drag low noise device illustratedin FIG. 13, taken along line 18-18. FIG. 18 depicts the low drag lownoise device subjected to a flow field and how fluid flows through thelow drag low noise device.

FIG. 19 depicts the low drag low noise device illustrated in FIG. 10subjected to a flow field.

FIG. 20 is a front perspective view of another low drag low noisedevice.

FIG. 21 is a sectional view of the low drag low noise device illustratedin FIG. 20, taken along line 21-21.

FIG. 22 is a sectional view of the low drag low noise device illustratedin FIG. 20, taken along line 22-22.

FIG. 23 is a rear perspective view of another low drag low noise device.

FIG. 24 is a rear view of the low drag low noise device illustrated inFIG. 23.

FIG. 25 is a top view of the low drag low noise device illustrated inFIG. 23.

FIG. 26 is a rear perspective view of another low drag low noise device.

FIG. 27 is a top view of the low drag low noise device illustrated inFIG. 25.

FIG. 28 is a rear view of the low drag low noise device illustrated inFIG. 25.

FIG. 29 is a perspective view of a motor vehicle with an attached lowdrag low noise device.

FIG. 30 is a partial sectional view of the motor vehicle and low draglow noise device illustrated in FIG. 29, taken along line 30-30.

FIG. 31 is a partial sectional view of another low drag low noise deviceattached a motor vehicle.

FIG. 32 is a partial sectional view of another low drag low noise deviceattached to a motor vehicle.

FIG. 33 is a top view of a portion of another low drag low noise device.The low drag low noise device is in a first configuration.

FIG. 34 is a side view of the low drag low noise device illustrated inFIG. 33. The low drag low noise device is in a second configuration.

FIG. 35 is a perspective view of a motor vehicle with an attached lowdrag low noise device.

FIG. 36 is a partial sectional view of the motor vehicle and low draglow noise device illustrated in FIG. 35, taken along line 36-36.

FIG. 37 is a partial sectional view of the motor vehicle and low draglow noise device illustrated in FIG. 35, taken along line 37-37.

FIG. 38 is a partial sectional view of a motor vehicle with an attachedlow drag low noise device.

FIG. 39 is a perspective view of a motor vehicle with an attached lowdrag low noise device.

FIG. 40 is a partial sectional view of the motor vehicle and low draglow noise device illustrated in FIG. 39, taken along line 40-40.

FIG. 41 is a partial sectional view of another low drag low noise deviceattached to a motor vehicle.

FIG. 42 is a partial sectional view of another low drag low noise deviceattached to a motor vehicle.

FIG. 43 is a perspective view of a motor vehicle with an attached lowdrag low noise device.

DETAILED DESCRIPTION

The following description and the referenced drawings provideillustrative examples of that which the inventor regards as hisinventions. As such, the embodiments discussed herein are merelyexemplary in nature and are not intended to limit the scope of theinventor's inventions, the claims, or their protection, in any manner.Rather, the description and illustration of these illustrative examplesserve to enable a person of ordinary skill in the relevant art topractice the inventions.

The use of “e.g.,” “etc.,” “for instance,” “in example,” “for example,”and “or” and grammatically related terms indicates non-exclusivealternatives without limitation, unless otherwise noted. The use of“including” and grammatically related terms means “including, but notlimited to,” unless otherwise noted. The use of the articles “a,” “an,”and “the” are meant to be interpreted as referring to the singular aswell as the plural, unless the context clearly dictates otherwise. Thus,for example, reference to “an opening” includes two or more suchopenings, and the like. The use of “optionally,” “alternatively,” andgrammatically related terms means that the subsequently describedelement, event or circumstance may or may not be present/occur, and thatthe description includes instances where said element, event orcircumstance occurs and instances where it does not. The use of“preferred,” “preferably,” and grammatically related terms means that aspecified element or technique is more acceptable than another, but notthat such specified element or technique is a necessity, unless thecontext clearly dictates otherwise. The use of “exemplary”, means “anexample of” and is not intended to convey a meaning of an ideal orpreferred embodiment. The use of “attached” refers to the fixed,releasable, or integrated association of two or more elements and/ordevices. Thus, the term “attached,” and grammatically related terms,includes releasably attaching or fixedly attaching two or more elementsand/or devices. The use of “diameter” refers to the length of a straightline passing from side to side through the center of a body, element, orfeature, and does not impart any structural configuration on the body,element, or feature. The use of “circumference” refers to a displacementmeasured along the exterior surface area of a body, element, or featureand does not impart any structural configuration of the body, element,or feature (e.g., the perimeter of a body, element, or feature). Wordsof approximation (e.g., “substantially,” “generally,” “about”), as usedin context of the specification and figures, are intended to take ontheir ordinary and customary meanings, which denote approximation,unless the context clearly dictates otherwise.

Several exemplary low drag low noise devices are described herein. Anyof the exemplary devices can be attached to any suitable object usingany suitable method of attachment, and skilled artisans will be able toselect a suitable low drag low noise device to attach to an object and asuitable method of attachment according to a particular embodiment basedon various considerations, such as the material(s) that form the object.In the embodiments described herein, some of the low drag low noisedevices are described as a side view mirror that can be attached to amotor vehicle such that the motor vehicle has reduced drag and noisefeatures. In other embodiments, the low drag low noise devices aredescribed as being attached to, or formed as part of, a motor vehicle.The motor vehicle can comprise any suitable motor vehicle, such as thosedescribed herein (e.g., automobile, car, truck, motorcycle, boat,locomotive, aircraft, airplane, projectile). It is to be noted, however,that the elements, features, and components described herein are notlimited to these examples and can be used in any suitable manner tocreate any suitable low drag low noise device.

FIGS. 5, 6, 7, 8, 9, 10, 11, and 11A illustrate a first low drag lownoise device 10. The low drag low noise device 10 comprises a lengthwiseaxis 11, an outer body 12, inner body 14, mirror 16, and a plurality ofconnection fins 18.

The outer body 12, inner body 14, and each connection fin of theplurality of connection fins 18 of low drag low noise device 10 can beformed of any suitable material and manufactured using any suitabletechnique. Skilled artisans will be able to select a suitable materialto form an outer body, inner body, and connection fin(s) of a low draglow noise device and a suitable technique to manufacture the outer body,inner body, and the connection fin(s) of a low drag low noise deviceaccording to a particular embodiment based on various considerations,including the intended use of the low drag low noise device. Examplematerials considered suitable to form the outer body, inner body, andconnection fin(s) of a low drag low noise device include metals,plastics, combinations of metals and plastics, composite materials, andany other material considered suitable for a particular embodiment.Example methods of manufacture considered suitable to manufacture theouter body, inner body, and connection fin(s) of a low drag low noisedevice include injection molding, machining, 3D printing, and any othermethod of manufacture considered suitable for a particular embodiment.

The outer body 12 comprises a first end 22, a second end 24, an outersurface 26, and a length 27. The outer body 12 defines a first opening28, a second opening 30, an inner surface 32, and a passageway 34.

In the illustrated embodiment of FIGS. 5, 6, 7, 8, 9, 10, 11, and 11A,the first end 22 of the outer body 12 comprises a generally circularouter surface 26 and the second end 24 of the outer body 12 comprises agenerally rectangular outer surface 26. The generally circular outersurface 26 of the first end 22 is lofted into the general rectangularouter surface 26 of the second end 24. The first end 22 has an outsidediameter 23 and the second end 24 has an outside diameter 25. Theoutside diameter 23 of the first end 22 is less than the outsidediameter 25 of the second end 24. This provides a streamlined andaerodynamic shape. In this illustrated embodiment, the generallyrectangular outer surface 26 of the second end 24 has a width equal to7.0 centimeters and a height of 5 centimeters. While particular widthsand heights have been illustrated other widths and heights areconsidered suitable.

The length 27 of the outer body 12 extends from the first end 22 to thesecond end 24 of the outer body 12 and is measured on an axis that isparallel to the lengthwise axis 11 of the low drag low noise device 10.The outer body of a low drag low noise device can have any suitablelength, and skilled artisans will be able to select a suitable lengthfor the outer body of a low drag low noise device according to aparticular embodiment based on various considerations, including thedesired flow characteristics intended to be achieved. Example lengthsconsidered suitable for the outer body of a low drag low noise deviceinclude lengths equal to 5.0 centimeters, equal to about 5.0centimeters, equal to 7.0 centimeters, equal to about 7.0 centimeters,equal to between 1.0 centimeter and 10.0 centimeters, equal to betweenabout 1.0 centimeter and about 10.0 centimeters, equal to between 5.0centimeters and 7.0 centimeters, and equal to between about 5.0centimeters and about 7.0 centimeters.

The first opening 28 is defined on the first end 22 of the outer body12, has a curved leading edge, and has a diameter 29 that is measured onan axis that is perpendicular to the lengthwise axis 11 of the low draglow noise device 10. The second opening 30 is defined on the second end24 of the outer body 12 and has a diameter 31 that is measured on anaxis that is perpendicular to the lengthwise axis 11 of the low drag lownoise device 10. In the embodiment illustrated in FIGS. 5, 6, 7, 8, 9,10, 11, and 11A, the diameter 29 of the first opening 28 is less thanthe diameter 31 of the second opening 30.

While the first opening 28 has been illustrated as generally circularand the second opening 30 has been illustrated as generally rectangular,the first opening and second opening defined by an outer body can haveany suitable structural configuration. Skilled artisans will be able toselect a suitable structural configuration for a first opening and/orsecond opening defined by an outer body according to a particularembodiment based on various considerations, including the desired flowcharacteristics intended to be achieved by a low drag low noise device.Example structural configurations considered suitable for a firstopening and/or second opening defined by an outer body include circular,triangular, square, rectangular, elliptical, oval, and any otherstructural configuration considered suitable for a particularembodiment.

While the first end 22 of the outer body 12 has been illustrated asdefining a first opening 28, the first end of an outer body can defineany suitable number of openings, and skilled artisans will be able toselect a suitable number of openings to define on the first end of anouter body according to a particular embodiment based on variousconsiderations, including the desired flow characteristics intended tobe achieved by a low drag low noise device. Example number of openingsconsidered suitable to define on the first end of an outer body includeone, at least one, two, a plurality, three, four, five, and any othernumber considered suitable for a particular embodiment.

While the first end 22 of the outer body 12 has been illustrated ashaving a curved leaded edge, the first end of an outer body can have anystructural configuration, and skilled artisans will be able to select asuitable structural configuration for the first end of an outer bodyaccording to a particular embodiment based on various considerations,including the desired effect the first end has on fluid during use.Example alternative structural arrangements considered suitable for thefirst end of an outer body include rounded, flat, pointed, tapered, andany other structural arrangement considered suitable for a particularembodiment.

The inner surface 32 of the outer body 12 extends from the first opening28 to the second opening 30 and defines the passageway 34, which extendsthrough the outer body 12. As illustrated best in FIGS. 10 and 11, theinner surface 32 of the outer body 12 extends away from the lengthwiseaxis 11 of the low drag low noise device 10 from the first end 22 to thesecond end 24 of the outer body 12. Thus, the passageway 34 is formedsuch that it diverges and has a diameter that increases from the firstend 22 to the second end 24 of the outer body 12.

While not illustrated, the outer body 12 can include one or morestructures to attach the outer body 12 to another component (e.g., thedoor, or body, of a motor vehicle). Skilled artisans will be able toselect a suitable structure to include on the outer body of a low draglow noise device according to a particular embodiment based on variousconsiderations, including the structural arrangement of the component towhich the low drag low noise device is intended to be attached. Forexample, the outer body of a low drag low noise device can include oneor more attachment mechanisms or attachment arms to attach the low draglow noise device to a component, such as a motor vehicle.

The outer body 12 has a thickness that decreases from the first end 22to the second end 24 of the outer body 12. As best illustrated in FIG.10, the outer body 12 has a first thickness 33′ between the first end 22and the second end 24 of the outer body 12 and a second thickness 33″between the first thickness 33′ and the second end 24 of the outer body12. The second thickness 33″ is less than the first thickness 33′. Thefirst thickness 33′ is measured on an axis that is disposedperpendicular to the lengthwise axis 11 of the low drag low noise device10. The second thickness 33″ is measured on an axis that is disposedperpendicular to the lengthwise axis 11 of the low drag low noise device10.

While the outer body 12 has been illustrated as having a thickness thatdecreases from the first end 22 to the second end 24, the outer body ofa low drag low noise device can have any suitable thickness. Skilledartisans will be able to select a suitable thickness for the outer bodyof a low drag low noise device according to a particular embodimentbased on various considerations, including the desired effect of theouter body on fluid that is intended to pass around and through the lowdrag low noise device. For example, the outer body can have a thicknessthat is constant, substantially constant, that is greater at the secondend than at the first end of the outer body, or any other configurationconsidered suitable for a particular embodiment.

In the illustrated embodiment, the inner body 14 is partially disposedwithin the passageway 34 defined by the outer body 12 and is attached tothe outer body 12 using the plurality of connection fins 18, asdescribed in more detail herein. The inner body 14 comprises a first end38, a second end 40, a length 41, and an outer surface 42 that has acircumference.

The first end 38 of the inner body 14 is disposed outside of thepassageway 34 defined by the outer body 12 and has a curved leadingedge. First end 38 is disposed outside of passageway 34 such that asection 44 of the inner body 14 is disposed outside of the passageway 34defined by the outer body 12. However, alternative embodiments caninclude an inner body that has a first end disposed entirely within thepassageway defined by an outer body, or a first end that is disposed ona plane that contains the first end of the outer body. The section 44 ofthe inner body 14 disposed outside of the passageway 34 extends from thefirst end 38 of the inner body 14 toward the second end 40 of the innerbody 14 to a section end 44′. Section 44 has a generally conical outersurface 42 that is lofted toward the second end 40 of the inner body 14and increases in diameter from the first end 38 of the inner body 14 tothe section end 44′. The second end 40 of the inner body 14 comprises agenerally rectangular outer surface 42. The generally conical outersurface 42 of section 44 is lofted into the generally rectangular outersurface 42 of the second end 40 such that the inner body 14 tapers fromthe second end 40 to the first end 38.

The first end 38 of the inner body 14 has an outside diameter 39 and thesecond end 40 of the inner body 14 has an outside diameter 43. Theoutside diameter 39 of the first end 38 is measured on an axis that isdisposed perpendicular to the lengthwise axis 11 of the low drag lownoise device 10. The outside diameter 43 of the second end 40 ismeasured on an axis that is disposed perpendicular to the lengthwiseaxis 11 of the low drag low noise device 10. The outside diameter 39 ofthe first end 38 is less than the outside diameter 43 of the second end40.

The length 41 of the inner body 14 extends from the first end 38 to thesecond end 40 of the inner body 14 and is measured on an axis that isparallel to the lengthwise axis 11 of the low drag low noise device 10.The length 41 of the inner body 14 is different than the length 27 ofthe outer body 12. In the embodiment illustrated, the length 41 of theinner body 14 is greater than the length 27 of the outer body 12.Alternatively, the length of the inner body of a low drag low noisedevice can be less than, or equal to, the length of the outer body ofthe low drag low noise device.

The inner body of a low drag low noise device can have any suitablelength, and skilled artisans will be able to select a suitable lengthfor the inner body of a low drag low noise device according to aparticular embodiment based on various considerations, including thedesired flow characteristics intended to be achieved. Example lengthsconsidered suitable for the inner body of a low drag low noise device,such as a side view mirror, include lengths equal to 10.0 centimeters,equal to about 10.0 centimeters, equal to 15.0 centimeters, equal toabout 15.0 centimeters, equal to between 1.0 centimeter and 20.0centimeters, equal to between about 1.0 centimeter and about 20.0centimeters, equal to between 10.0 centimeters and 15.0 centimeters, andequal to between about 10.0 centimeters and about 15.0 centimeters.

While the first end 38 of the inner body 14 has been illustrated ashaving a curved leaded edge, the first end of an inner body can have anystructural configuration, and skilled artisans will be able to select asuitable structural configuration for the first end of an inner bodyaccording to a particular embodiment based on various considerations,including the desired effect the first end has on fluid during use.Example alternative structural arrangements considered suitable for thefirst end of an inner body include rounded, flat, pointed, tapered, andany other structural arrangement considered suitable for a particularembodiment.

The mirror 16 is attached to the second end 40 of the inner body 14. Themirror can be formed of any material capable of reflecting images on thesurface of the mirror 16 and can comprise any suitable shape (e.g.,flat, concave, convex). The mirror 16 can be attached to the second end40 of the inner body 14 using any suitable method of attachment, andskilled artisans will be able to select a suitable method to attach amirror to the inner body of a low drag low noise device according to aparticular embodiment based on various considerations, including thematerial(s) that forms the mirror and/or the inner body. Example methodsof attachment considered suitable between a mirror and an inner bodyinclude using adhesives, mechanical attachment devices, and any othermethod of attachment considered suitable for a particular embodiment.

In the illustrated embodiment, the mirror 16 is attached to the secondend 40 of the inner body 14 such that it is disposed on a plane that isorthogonal to the lengthwise axis 36 of the inner body 14. However, themirror of a low drag low noise device can be disposed at other anglesrelative to the lengthwise axis of an inner body, or can be attached tothe inner body such that the angle at which the mirror is disposed canbe altered as desired.

While the outer body 12 and the inner body 14 have been illustrated ashaving particular structural configurations, the outer body and innerbody of a low drag low noise device can have any suitable structuralarrangement. Skilled artisans will be able to select a suitablestructural arrangement for the outer body and inner body of a low draglow noise device according to a particular embodiment based on variousconsiderations, including the desired reduction in drag and/or noiseintended to be achieved. For example, the outer body of a low drag lownoise device can comprise a first end that has an outer surface that isgenerally rectangular, circular, conical, or elliptical, and/or a secondend that has an outer surface that is generally rectangular, circular,conical, or elliptical. While the inner body 14 has been illustrated ashaving a conical structural configuration, the inner body of a low draglow noise device can have any suitable structural arrangement, such as afirst end and/or second end that is generally rectangular, circular, orelliptical.

Each connection fin of the plurality of connection fins 18 has a firstend 48, a second end 50, and a thickness 52. As best illustrated in FIG.9, the first end 48 of each connection fin of the plurality ofconnection fins 18 is attached to the inner surface 32 of the outer body12 and the second end 50 is attached to the outer surface 42 of theinner body 14. In the illustrated embodiment, a connection fin of theplurality of connection fins 18 is disposed in each corner of thegenerally rectangular shaped inner surface 32 of outer body 12. Thethickness 52 of each connection fin of the plurality of connection fins18 is less than the second thickness 33″ of the outer body 12. Thisstructural arrangement provides a mechanism to minimize the impact eachconnection fin of the plurality of fins 18 has on the shape anddirection of fluid that is intended to flow between the outer body 12and the inner body 14, as described in more detail herein.

Each connection fin of the plurality of connection fins 18 can beattached to the outer body 12 and the inner body 14 using any suitablemethod of attachment. Skilled artisans will be able to select a suitablemethod of attachment between a connection fin and an outer body and/orinner body according to a particular embodiment based on variousconsiderations, including the material(s) that forms the connection fin,the outer body, and/or the inner body. Example methods of attachmentconsidered suitable include using adhesives, mechanical connectors,and/or forming the outer body, inner body, and each connection as anintegral component.

While each fin of the plurality of connection fins 18 has beenillustrated as disposed at a particular location between the outer body12 and the inner body 14, a connection fin can be disposed at anysuitable location between the outer body and the inner body of a lowdrag low noise device. Skilled artisans will be able to select asuitable position for a connection fin according to a particularembodiment based on various considerations, including the structuralconfiguration between the outer body and the inner body.

While each fin of the plurality of fins 18 has been illustrated ashaving an elongated structural configuration, a fin can have anysuitable structural configuration, and skilled artisans will be able toselect a suitable structural configuration for a fin according to aparticular embodiment based on various considerations, including thedesired velocity and angle at which fluid is intended to flow through alow drag low noise device. For example, a fin can be formed such that itis circular (e.g., screw), elliptical, or such that it defines anairfoil oriented toward the first or second end of the outer body.

While the low drag low noise device 10 has been illustrated as includinga plurality of connection fins 18, a low drag low noise device caninclude any suitable number of connection fins. Skilled artisans will beable to select a suitable number of connection fins to include on a lowdrag low noise device according to a particular embodiment based onvarious considerations, including the desired velocity and angle atwhich fluid is intended to flow through the low drag low noise device.Example number of connection fins considered suitable to include in alow drag low noise device include, one, at least one, two, a plurality,three, four, five, and any other number considered suitable for aparticular embodiment.

While the inner body 14 has been illustrated as attached to the outerbody 12 using a plurality of connection fins 18, the inner body of a lowdrag low noise device can be attached to the outer body of the low draglow noise device using any suitable method of attachment. Skilledartisans will be able to select a suitable method of attachment betweenthe inner body and outer body of a low drag low noise device accordingto a particular embodiment based on various considerations, includingthe material(s) that forms the inner body and/or outer body.

In the illustrated embodiment, the inner surface 32 of the outer body 12and the outer surface 42 of the inner body 14 cooperatively define achannel 54 within the passageway 34 defined by the outer body 12. Thechannel 54 extends along the entire length 27 of the outer body 12 andis unobstructed along its length, except for the plurality of connectionfins 18. Alternatively, when an inner body is entirely disposed withinthe passageway defined by an outer body, the channel can extend along aportion of the length of an outer body. The channel 54 has a first end54′ and a second end 54″. During use, fluid enters the channel 54 at thefirst end 54′ and exits the channel 54 at the second end 54″. The innersurface 32 of the outer body 12 and the outer surface 42 of the innerbody 14 define the channel 54 about the entire circumference of theouter surface 42 of the inner body 14. Alternatively, a channel can bedefined about a portion of the circumference of the outer surface of aninner body.

As best illustrated in FIG. 11, the channel 54 has a firstcross-sectional area 56 disposed on a first plane 57 that is disposedorthogonal to the lengthwise axis 11 of the low drag low noise device10. The first plane 57 is disposed between the first end 38 and thesecond end 40 of the inner body 14. The channel 54 has a secondcross-sectional area 58 disposed on a second plane 59 that is disposedorthogonal to the lengthwise axis 11 of the low drag low noise device10. The second plane 59 is disposed between the first plane 57 and thesecond end 40 of the inner body 14. The first cross-sectional area 56 isgreater than the second cross-sectional area 58. Thus, the inner surface32 of the outer body 12 and the outer surface 42 of the inner body 14converge from the first end 38 of the inner body 14 to the second end 40of the inner body 14. By reducing the cross-sectional area of thechannel 54 from the first end 38 of the inner body 14 to the second end40 of the inner body 14, fluid accelerates as it is passed through thechannel 54 and exits the low drag low noise device 10 at a velocity thatis greater than the velocity at which it entered the low drag low noisedevice 10.

Any suitable ratio between the first cross-sectional area 56 and secondcross-sectional area 58 can be used to form a low drag low noise device10, and skilled artisans will be able to select a suitable ratio betweenthe first-cross sectional area and the second cross-sectional areaaccording to a particular embodiment based on various considerations,including the desired amount of acceleration intended to be applied to afluid that travels through the channel of the low drag low noise device.Example ratios considered suitable between the first cross-sectionalarea 56 and the second cross-sectional area 58 include ratios equal toequal to 1.0, equal to about 1.0, equal to 1.1, equal to about 1.1,equal to 2.0, equal to about 2.0, equal to 3.0, equal to about 3.0,equal to 8.0, equal to about 8.0, equal to 10.0, equal to about 10.0,equal to between 1.0 and 10, and equal to between about 1.0 and about10.

In the illustrated embodiment, the distance between the inner surface 32of the outer body 12 and the outer surface 42 of the inner body 14 isconstant about the circumference of the inner body 14 and can compriseany suitable distance. Example distances considered suitable for a lowdrag low noise device, such as a side view mirror, include distancesequal to 1.0 millimeter, equal to about 1.0 millimeter, equal to 4.0millimeters, equal to about 4.0 millimeters, equal to between 1.0millimeter to 4.0 millimeters, and equal to about 1.0 millimeter toabout 4.0 millimeters.

While the distance between the inner surface 32 of the outer body 12 andthe outer surface 42 of the inner body 14 has been illustrated asconstant at the first end 22 of the outer body 12 and the second end 24of the outer body 12, the distance between the inner surface of an outerbody and the inner surface of an inner body can vary about thecircumference of the inner body. For example, the inner surface of anouter body can be disposed both a first distance and second distancefrom the outer surface of an inner body on a plane that is orthogonal tothe lengthwise axis of a low drag low noise device. The first distancecan be the same as, or different than, the second distance.

The inner surface 32 of the outer body 12 and the outer surface 42 ofthe inner body 14 are configured to allow a fluid (e.g., air) to passthrough the channel 54 from the first end 22 of the outer body 12 to thesecond end 24 of the outer body 12 such that the fluid exits the channel54 at the second end 24 of the outer body 12 at an angle 60. The angle60 is directed toward the lengthwise axis 11 of the low drag low noisedevice 10 and away from the second end 24 of the inner body 14.Alternatively, the angle 60 can be directed toward an axis that isparallel to the freestream flow of fluid through which the low drag lownoise device 10 is traveling and that extends through a portion of theinner body 14 and/or a portion of the mirror 16 of the low drag lownoise device 10. Angle 60 is measured relative to an axis that containsthe second end 24 of the outer body 12 and that is parallel to thelengthwise axis 11 of the low drag low noise device 10. Alternatively,the angle 60 can be measured relative to an axis that contains thesecond end 24 of the outer body 12 and that is parallel to thefreestream flow of fluid through which the low drag low noise device 10is traveling. While angle 60 has been illustrated as constant about thecircumference of the second end 40 of the inner body 14, angle 60 canalternatively vary about the circumference of the second end 40 of innerbody 14. For example, fluid can exit the channel defined by a low draglow noise device at a first angle and a second angle at the second endof channel. The first angle can be different from, or the same as, thesecond angle and can comprise any suitable angle, such as thosedescribed herein with respect to angle 60.

Angle 60 can comprise any suitable angle, and skilled artisans will beable to select a suitable angle to direct fluid as it exits a low draglow noise device according to a particular embodiment based on variousconsiderations, including the desired pressure and/or vortex sheddingintended to be achieved. In the illustrated embodiment, angle 60 isequal to 25 degrees. Other angles considered suitable include anglesequal to 0 degrees, equal to about 0 degrees, equal to 5 degrees, equalto about 5 degrees, equal to 45 degrees, equal to about 45 degrees,equal to 50 degrees, equal to about 50 degrees, equal to between 0degrees and 50 degrees, equal to between about 0 degrees and about 50degrees, equal to between 5 degrees and 50 degrees, and equal to betweenabout 5 degrees and about 50 degrees.

In the illustrated embodiment, at the second end 24 of the outer body12, the inner surface 32 curves toward the lengthwise axis 11 of the lowdrag low noise device 10. At the second end 40 of the inner body 14, theouter surface 42 curves toward the lengthwise axis 11 of the low draglow noise device 10.

As best illustrated in FIG. 11A, the inner surface 32 of the outer body12 has an inner surface section 61 that extends from a first end 61′ toa second end 61″. The first end 61′ is disposed between the first end 22and second end 24 of the outer body 12. The second end 61″ of the innersurface section 61 is disposed between the first end 61′ of the innersurface section 61 and the second end 24 of the outer body 12. The innersurface section 61 extends toward the lengthwise axis 11 of the low draglow noise device 10 from the first end 61′ to the second end 61″ at anangle 61′″. Alternatively, the inner surface section 61 can extend at anangle 61′″ toward an axis that is parallel to the freestream flow offluid through which the low drag low noise device 10 is travelling andthat extends through a portion of the inner body 14 and/or a portion ofthe mirror 16 of the low drag low noise device 10. Angle 61′″ cancomprise any suitable angle, such as those described herein relative toangle 60. Angle 61′″ is measured relative to an axis that contains thesecond end 24 of the outer body 12 and is parallel to the lengthwiseaxis 11 of the low drag low noise device 10. Alternatively, angle 61′″can be measured relative to an axis that contains the second end 24 ofthe outer body 12 and that is parallel to the freestream flow of fluidthrough which the low drag low noise device 10 is travelling. Whileangle 61′″ has been illustrated as constant about the circumference ofthe inner surface 32 of the outer body 12, angle 61′″ can alternativelyvary about the circumference of the inner surface 32 of the outer body12. For example, a first section of the inner surface of the outer body12 can be defined at a first angle, such as those described herein, anda second section of the inner surface of the outer body 12 can bedefined at a second angle, such as those described herein. The firstangle can be different from, or the same as, the second angle.

As best illustrated in FIG. 11A, the outer surface 42 of the inner body14 has an outer surface section 62 that extends from a first end 62′ toa second end 62″. The first end 62′ is disposed between the first end 38and second end 40 of the inner body 14. The second end 62″ of the outersurface section 62 is disposed between the first end 62′ of the outersurface section 62 and the second end 40 of the inner body 14. The outersurface section 62 extends toward the lengthwise axis 11 of the low draglow noise device 10 from the first end 62′ to the second end 62″ at anangle 62′″. Alternatively, the outer surface section 62 can extend at anangle 62′″ toward an axis that is parallel to the freestream flow offluid through which the low drag low noise device 10 is travelling andthat extends through a portion of the inner body 14 and/or a portion ofthe mirror 16 of the low drag low noise device 10. Angle 62′″ cancomprise any suitable angle, such as those described herein relative toangle 60. Angle 62′″ is measured relative to an axis that contains thesecond end 40 of the inner body 14 and is parallel to the lengthwiseaxis 11 of the low drag low noise device 10. Alternatively, angle 62′″can be measured relative to an axis that contains the second end 40 ofthe inner body 14 and that is parallel to the freestream flow of fluidthrough which the low drag low noise device 10 is travelling. Whileangle 62′″ has been illustrated as constant about the circumference ofthe outer surface 42 of the inner body 14, angle 62′″ can alternativelyvary about the circumference of the outer surface 42 of the inner body14. For example, a first section of the outer surface of the inner body14 can be defined at a first angle, such as those described herein, anda second section of the outer surface of the inner body 14 can bedefined at a second angle, such as those described herein. The firstangle can be different from, or the same as, the second angle.

Alternative to both the inner surface 32 of the outer body 12 and theouter surface 42 of the inner body 14 extending toward the lengthwiseaxis 11 of the low drag low noise device 10, or an axis that is parallelto the freestream flow through which the low drag low noise device 10 istravelling, one of the inner surface 32 of the outer body 12 or theouter surface 42 inner body 14 can extend toward the lengthwise axis 11of the low drag low noise device 10, or the axis that is parallel to thefreestream flow through which the low drag low noise device 10 istravelling. While angle 61′″ and angle 62′″ have been illustrated asequal to one another, angle 61′″ and angle 62′″ can be different fromone another and can comprise any suitable angle, such as those describedherein with respect to angle 60.

During travel, the channel 54 directs the flow of fluid (e.g., air)through the low drag low noise device 10 to accomplish a reduction innoise and drag relative to a device that does not define a channelthrough the device. During use, fluid enters the low drag low noisedevice 10 through the first opening 28 of the outer body 12 and isdirected through channel 54 between the outer body 12 and the inner body14 and exits through the second opening 30 defined by the outer body 12as a jet of fluid 64. The jet of fluid 64 travels at a specific velocityand at angle 60. This is best shown in FIGS. 10 and 11. Based on angle60, the noise level and drag is reduced as a result of jet of fluid 64altering the base flow relative to a device that does not include achannel. In addition, as a result of the jet of fluid 64 convergingtoward the lengthwise axis 11 of the low drag low noise device 10 asmooth virtual trailing edge, or boat-tail, is created, as illustratedin FIG. 19. This smooth trailing edge, or boat-tail, prevents or reducesvortex shedding and increases base pressure relative to devices that donot include a channel, such as those illustrated in FIGS. 1 through 4.By reducing vortex shedding and increasing the base pressure, the noiseand drag produced by the low drag low noise device 10 is reducedrelative to devices that do not include a channel, such as thoseillustrated in FIGS. 1 through 4.

The angle and velocity at which the jet of fluid 64 exits the channel 54will be based on a number of characteristics, such as the structuralarrangement of the outer surface 26 of the outer body 12, the structuralarrangement between the outer body 12 and the inner body 14 at the firstend 22 and second end 24 of the outer body 12, the structuralarrangement between the outer body 12 and the inner body 14 alongchannel 54, the first cross-sectional area 56, and/or the secondcross-sectional area 58. It is to be understood that the abovecharacteristics of the low drag low noise device 10 may be modifiedwithin the scope of the present disclosure in the interest of obtainingthe optimum exit angle and velocity which results in the greatestreduction in noise and/or drag.

FIGS. 12, 13, 14, 15, 16, 17, and 18 illustrate another low drag lownoise device 110. Low drag low noise device 110 is similar to the lowdrag low noise device 10 illustrated in FIGS. 5, 6, 7, 8, 9, 10, 11 and11A and described above, except as detailed below. Reference numbers inFIGS. 12, 13, 14, 15, 16, 17, and 18 refer to the same structuralelement or feature referenced by the same number in FIGS. 5, 6, 7, 8, 9,10, 11 and 11A, offset by 100. Thus, low drag low noise device 110comprises an outer body 112, an inner body 114, a mirror 116, and aplurality of connection fins 118.

In the embodiment illustrated in FIGS. 12, 13, 14, 15, 16, 17, and 18,the mirror 116 defines a passageway 168 that extends through thethickness of the mirror 116. In addition, the inner body 114 defines afirst opening 170, a second opening 172, and a passageway 174. The firstopening 170 is defined on the first end 138 of the inner body 114. Thesecond opening 172 is defined on the second end 140 of the inner body114. The passageway 174 extends from the first opening 170 to the secondopening 172 and traverses the length 141 of the inner body 114. Thesecond opening 172 defined by the inner body 114 is in communicationwith the passageway 168 defined by the mirror 116.

In the illustrated embodiment, the passageway 168 defined by the mirror116 and the passageway 174 defined by the inner body 114 have the samediameter and the diameter of passageway 174 is constant along itslength. It is to be noted, however, that in alternative embodiments thediameter of passageway 168 and the diameter of passageway 174 can bedifferent than one another. In addition, alternative embodiments caninclude a passageway 174 that converges, or diverges, from the first end138 of the inner body 114 to the second end 140 of the inner body 144.

The passageway 168 defined by the mirror 116 and the passageway 174defined by the inner body 114 can have any suitable diameter. Skilledartisans will be able to select a suitable diameter for a passagewaydefined by a mirror and a passageway defined by an inner body, accordingto a particular embodiment based on various considerations, includingthe desired flow characteristics intended to be achieved at the secondend of the inner body. Example diameters considered suitable for apassageway defined by a mirror and/or a passageway defined by an innerbody include diameters equal to 3.0 millimeters, equal to about 3.0millimeters, equal to 5.0 millimeters, equal to about 5.0 millimeters,equal to between 1.0 millimeter and 7.0 millimeters, equal to betweenabout 1.0 millimeter and about 7.0 millimeters, equal to between 3.0millimeters and 5.0 millimeters, and equal to between about 3.0millimeters and about 5.0 millimeters.

While the passageway 174 has been illustrated as having a circularcross-sectional configuration, the passageway defined by the inner bodyof a low drag low noise device can have any structural configuration.Skilled artisans will be able to select a suitable structuralconfiguration for the passageway defined by an inner body according to aparticular embodiment based on various considerations, including thedesired volume of fluid intended to be passed through the passageway.Example cross-sectional configurations considered suitable for thepassageway defined by an inner body include rectangular, square,triangular, circular, elliptical, oval, and any other cross-sectionalconfiguration considered suitable for a particular embodiment.

While the passageway 174 has been illustrated as extending from a firstopening 170 to a second opening 172, a passageway defined by the innerbody of a low drag low noise device can extend from one or more openingson the first end of the inner body to one or more openings on the secondend of the inner body. For example, the passageway can extend from afirst opening on the first end of the inner body to a plurality ofopenings defined on the second end of the inner body that are incommunication with a plurality of passageways defined by the mirror. Theplurality of openings defined by the mirror and the second end of theinner body can optionally be distributed in a grid format. Thisconfiguration provides a mechanism for reducing the amount of viewingobstruction created on the mirror relative to an embodiment thatincludes a single opening defined on the mirror.

As illustrated in FIGS. 17 and 18, in addition to fluid travellingthrough channel 154, fluid will travel through passageway 168 defined bythe mirror 116 and passageway 174 defined by the inner body 114. Thisconfiguration provides a mechanism for reducing the stagnation pressureat the front of the low drag low noise device 110 and increases the basepressure at the rear of the low drag low noise device 110 relative to adevice that does not include a passageway defined by the inner body.Reducing the stagnation pressure and increasing the base pressurereduces the pressure differential found when comparing the pressure ofthe fluid (e.g., air) at the front of the low drag low noise device 110to the pressure of the fluid (e.g., air) at the rear of the low drag lownoise device 110. With the pressure differential between the front andthe rear of the low drag low noise device 110 reduced, the magnitude ofpressure drag forces that the low drag low noise device 110 is subjectedto is also reduced relative to a device that does not include apassageway defined by the inner body.

FIGS. 20, 21, and 22 illustrate another low drag low noise device 210.Low drag low noise device 210 is similar to the low drag low noisedevice 10 illustrated in FIGS. 5, 6, 7, 8, 9, 10, 11 and 11A anddescribed above, except as detailed below. Reference numbers in FIGS.20, 21, and 22 refer to the same structural element or featurereferenced by the same number in FIGS. 5, 6, 7, 8, 9, 10, 11 and 11A,offset by 200. Thus, low drag low noise device 210 comprises an outerbody 212, an inner body 214, a mirror 216, and a plurality of connectionfins (not shown).

In the embodiment illustrated in FIGS. 20, 21, and 22, each of the firstend 222 of the outer body 212, the second end 224 of the outer body 212,the first opening 228 defined by the outer body 212, the second opening230 defined by the outer body 212, the first end 238 of the inner body214, and the second end 240 of the inner body 214 comprises a generallyrectangular configuration. In addition, the outer body 212 has a height278 and a width 280.

The height 278 is measured on a plane that is orthogonal to thelengthwise axis 211 of the low drag low noise device 210. The width 280is measured on a plane that is orthogonal to the lengthwise axis 211 ofthe low drag low noise device 210. The height 278 is greater than thewidth 280 providing an elongated low drag low noise device 210.

FIGS. 23, 24, and 25 illustrate another low drag low noise device 310.Low drag low noise device 310 is similar to the low drag low noisedevice 10 illustrated in FIGS. 5, 6, 7, 8, 9, 10, 11, and 11A anddescribed above, except as detailed below. Reference numbers in FIGS.23, 24, and 25 refer to the same structural element or featurereferenced by the same number in FIGS. 5, 6, 7, 8, 9, 10, 11, and 11A,offset by 300. Thus, low drag low noise device 310 comprises an outerbody 312, an inner body 314, a mirror 316, and a plurality of connectionfins 318.

In the embodiment illustrated in FIGS. 23, 24, and 25, the second end324 of the outer body 312 defines a sinusoidal edge 384 and a portion ofthe outer surface 326 has a waved configuration that corresponds to theto the sinusoidal edge 384. Sinusoidal edge 384 is defined along a planethat is orthogonal to the lengthwise axis 311 of the low drag low noisedevice 310. The sinusoidal edge 384 comprises a plurality of peaks 386and troughs 388 and can comprise any suitable amplitude and frequency.This is illustrated best in FIG. 24. This structural arrangementprovides a mechanism for enhancing the mixture of fluid that passes overthe outer surface 326 of the outer body 312 and that travels throughchannel 354.

While the second end 324 of the outer body 312 has been described ashaving a sinusoidal edge 384, the second end of the outer body of a lowdrag low noise device can define any suitable structural configuration.Skilled artisans will be able to select a suitable structuralconfiguration for the second end of an outer body according to aparticular embodiment based on various considerations, including theflow characteristics intended to be achieve. Example structuralconfigurations considered suitable include curved, wavy, angled,sinusoidal, and any other structural configuration considered suitablefor a particular embodiment.

While the second end 324 of the outer body 312 and a portion of theouter surface 326 of the outer body 312 have been illustrated as havinga particular structural arrangement, the outer body of a low drag lownoise device can have any suitable structural arrangement. Skilledartisans will be able to select a suitable structural arrangement forthe outer body of a low drag low noise device according to a particularembodiment based on various considerations, including the flowcharacteristics intended to be achieved. For example, while FIGS. 23,24, and 25 illustrate a portion of the outer surface 326 of the outerbody 312 having a waved configuration that corresponds to the to thesinusoidal edge 384, the outer surface of an outer body can define asinusoidal configuration, or waved configuration, that corresponds tothe sinusoidal edge defined by the outer body.

The first end 354′ and second end 354″ of channel 354 can comprise anysuitable cross-sectional area, and skilled artisans will be able toselect a suitable cross-sectional area for the first end and second endof a channel according to a particular embodiment based on variousconsiderations, including the desired flow characteristics intended tobe achieved at the first end and/or second end of the channel. Exampleratios considered suitable between a first cross-sectional area at thefirst end of a channel (e.g., disposed on a first plane that isorthogonal to the lengthwise axis of a low drag low noise device) and asecond cross-sectional area at the second end of a channel (e.g.,disposed on a second plane that is orthogonal to the lengthwise axis ofthe low drag low noise device and parallel to the first plane) includeratios equal to equal to 1.0, equal to about 1.0, equal to 1.1, equal toabout 1.1, equal to 2.0, equal to about 2.0, equal to 3.0, equal toabout 3.0, equal to 8.0, equal to about 8.0, equal to 10.0, equal toabout 10.0, equal to between 1.0 and 10, and equal to between about 1.0and about 10.

FIGS. 26, 27, and 28 illustrate another low drag low noise device 410.Low drag low noise device 410 is similar to the low drag low noisedevice 10 illustrated in FIGS. 5, 6, 7, 8, 9, 10, 11, and 11A anddescribed above, except as detailed below. Reference numbers in FIGS.26, 27, and 28 refer to the same structural element or featurereferenced by the same number in FIGS. 5, 6, 7, 8, 9, 10, 11, and 11A,offset by 400. Thus, low drag low noise device 410 comprises an outerbody 412, an inner body 414, a mirror 416, and a plurality of connectionfins 418.

In the embodiment illustrated in FIGS. 26, 27, and 28, the second end424 of the outer body 412 defines a sinusoidal edge 484 along the lengthof the outer body 412. The sinusoidal edge 484 comprises a plurality ofpeaks 486 and troughs 488, as best illustrated in FIG. 27. Thesinusoidal edge 484 can comprise any suitable amplitude and frequency.The peaks 486 are disposed at the second end 424 of the outer body 412and the troughs 488 are disposed between the first end 422 and thesecond end 424 of the outer body 412. This structural arrangementprovides a mechanism for enhancing the mixture of fluid that passes overthe outer surface 426 of the outer body 412 and that travels throughpassageway 454.

While the second end 424 of the outer body 412 has been described ashaving a sinusoidal edge 484, the second end of the outer body of a lowdrag low noise device can define any suitable structural configuration.Skilled artisans will be able to select a suitable structuralconfiguration for the second end of an outer body according to aparticular embodiment based on various considerations, including theflow characteristics intended to be achieve. Example structuralconfigurations considered suitable include curved, wavy, angled,sinusoidal, and any other structural configuration considered suitablefor a particular embodiment.

The sinusoidal edge 484 can comprise any suitable amplitude (e.g., peakto peak amplitude) and frequency. Skilled artisans will be able toselect a suitable amplitude and frequency to define the second end of anouter body according to a particular embodiment based on variousconsiderations, including the desired flow characteristics intended tobe achieved at the second end of a channel. Example amplitudes (e.g.,peak to peak) considered suitable for the edge of the second end of anouter body include amplitudes equal to 1 time to 4 times the distancebetween the inner surface of the outer body and the outer surface of aninner body along a plane that is disposed orthogonal to the lengthwiseaxis of the low drag low noise device (e.g., at the second end of theinner body), amplitudes substantially equal to 1 time to 4 times thedistance between the inner surface of the outer body and the outersurface of an inner body along a plane that is disposed orthogonal tothe lengthwise axis of the low drag low noise device (e.g., at thesecond end of the inner body), and amplitudes equal to about 1 time to 4times the distance between the inner surface of the outer body and theouter surface of an inner body along a plane that is disposed orthogonalto the lengthwise axis of the low drag low noise device (e.g., at thesecond end of the inner body).

FIGS. 29 and 30 illustrate another low drag low noise device 510attached to a motor vehicle 600. Low drag low noise device 510 issimilar to the low drag low noise device 10 illustrated in FIGS. 5, 6,7, 8, 9, 10, 11, and 11A and described above, except as detailed below.Reference numbers in FIGS. 29 and 30 refer to the same structuralelement or feature referenced by the same number in FIGS. 5, 6, 7, 8, 9,10, 11, and 11A, offset by 500. Thus, low drag low noise device 510comprises an outer body 512, an inner body 514, and a plurality ofconnection fins 518.

In the illustrated embodiment, the mirror (e.g., mirror 16) has beenomitted and the low drag low noise device 510 is attached to the motorvehicle 600, as described in more detail herein. The motor vehicle 600comprises a front end 602, a rear end 604, a first side 606, a secondside 608, a roof 610, and an undercarriage 612.

In the embodiment illustrated, the first end 522 of the outer body 512comprises a generally rectangular outer surface 526 and the second end524 of the outer body 512 comprises a generally rectangular outersurface 526. The generally rectangular outer surface 526 of the firstend 522 extends to the general rectangular outer surface 526 of thesecond end 524 and toward the lengthwise axis 511 of the low drag lownoise device 510. The first end 522 has an outside diameter 523 and thesecond end 524 has an outside diameter 525. The outside diameter 523 ofthe first end 522 is greater than the outside diameter 525 of the secondend 524.

The first opening 528 is generally rectangular and is defined on thefirst end 522 of the outer body 512. The first opening 528 has a firstdiameter 529 and a second diameter 529′ that is measured on a plane thatis orthogonal to the lengthwise axis 511 of the low drag low noisedevice 510. The second opening 530 is defined on the second end 524 ofthe outer body 512, is a generally rectangular, and has a first diameter531 and a second diameter 531′ that is measured on a plane that isorthogonal to the lengthwise axis 511 of the low drag low noise device10. In the embodiment illustrated in FIGS. 29 and 30, the first diameter529 of the first opening 528 is greater than the first diameter 531 ofthe second opening 530 and the second diameter 529′ of the first opening528 is greater than the second diameter 531′ of the second opening 530.

While the first opening 528 has been illustrated as generallyrectangular and the second opening 530 has been illustrated as generallyrectangular, the first opening and second opening defined by an outerbody can have any suitable structural configuration, as describedherein.

The inner surface 532 of the outer body 512 extends from the firstopening 528 to the second opening 530 and defines the passageway 534,which extends through the outer body 512. In the illustrated embodiment,the inner surface 532 of the outer body 512 extends toward thelengthwise axis 511 of the low drag low noise device 510 from the firstend 522 to the second end 524 of the outer body 512. Thus, thepassageway 534 is formed such that it converges and has a length and awidth that decreases from the first end 522 to the second end 524 of theouter body 512.

In the illustrated embodiment, the inner body 514 is entirely disposedwithin the passageway 534 defined by the outer body 512 and is attachedto the outer body 512 using the plurality of connection fins 518. Theinner body 514 comprises a first end 538, a second end 540, a length541, an outer surface 542, and an inner surface 546.

The inner surface 546 of the inner body 514 is generally rectangular andis attached to the motor vehicle 600 (e.g., the trailer 614) using anysuitable method or technique. The first end 538 of the inner body 514 isdisposed within the passageway 534 defined by the outer body 512. Thesecond end 540 of the inner body 514 is disposed on a plane thatcontains the second end 524 of the outer body 512, the rear end 604 ofthe motor vehicle 600, and is disposed orthogonal to the lengthwise axis511 of the low drag low noise device 510. However, alternativeembodiments could include, but are not limited to, a second end of aninner body that is not disposed on a plane that contains the second endof an outer body or the rear end of the vehicle, or that is disposed ona plane that contains the second end of an outer body or the rear end ofthe vehicle. The outer surface 542 of the inner body 514 extends fromthe first end 538, curves away from the lengthwise axis 511 of the lowdrag low noise device 510 along a first portion of the inner body 514,and curves toward the lengthwise axis 511 of the low drag low noisedevice 510 along a second portion of the inner body 514 to the secondend 540. The first portion of the inner body 514 is disposed between thefirst end 538 and the second end 540 and the second portion of the innerbody is disposed between the first portion and the second end 540 of theinner body 514.

While the inner body 514 has been illustrated as having an inner surface546 that has a generally rectangular shape, the inner surface of aninner body can have any suitable shape. Skilled artisans will be able toselect a suitable shape to configure the inner surface of an inner bodyaccording to a particular embodiment based on various considerations,including the shape and/or structural configuration of the vehicle, orcomponent, to which the low drag low noise device is being attached.Example shapes considered suitable to form the inner surface of an innerbody include, but are not limited to, generally rectangular, circular,square, elliptical, oval, oblong, and any other shape consideredsuitable for a particular embodiment.

The inner body 514 of low drag low noise device 510 can be attached tothe motor vehicle 600 (e.g., trailer 614) using any suitable method ortechnique, and skilled artisans will be able to select a suitable methodor technique to attach a low drag low noise device to a vehicle based onvarious considerations, including the material(s) that forms the lowdrag low noise device and/or the vehicle. Example methods and techniquesconsidered suitable to attach a low drag low noise device to anothercomponent, such as a vehicle, include using adhesives, mechanicalconnections (e.g., screws, nuts, bolts), welding the low drag low noisedevice to the component, using one or more straps, and any other methodor technique considered suitable for a particular embodiment.Optionally, the inner surface 514 can be formed as part of a vehicle(e.g., trailer).

The first end 538 of the inner body 514 has a first diameter 539 and asecond diameter 539′ and the second end 540 of the inner body 514 has afirst diameter 543 and a second diameter 543′. The first diameter 539and second diameter 539′ of the first end 538 is measured on a planethat is disposed orthogonal to the lengthwise axis 511 of the low draglow noise device 510. The first diameter 543 and second diameter 543′ ofthe second end 540 is measured on a plane that is disposed orthogonal tothe lengthwise axis 511 of the low drag low noise device 510. The firstdiameter 539 of the first end 538 is equal to the first diameter 543 ofthe second end 540. The second diameter 539′ of the first end 538 isequal to the second diameter 543′ of the second end 540.

The length 541 of the inner body 514 extends from the first end 538 tothe second end 540 of the inner body 514 and is measured on an axis thatis parallel to the lengthwise axis 511 of the low drag low noise device510. The length 541 of the inner body 514 is different than the length527 of the outer body 512. In the embodiment illustrated, the length 541of the inner body 514 is less than the length 527 of the outer body 512.Alternatively, the length of the inner body of a low drag low noisedevice can be greater than, or equal to, the length of the outer body ofthe low drag low noise device.

In the illustrated embodiment, the low drag low noise device 510 isattached to the vehicle 600 (e.g., trailer 614) between the front end602 and rear end 604 of the vehicle 600 such that the second end 524 ofthe outer body 512 and the second end 540 of the inner body 514 aredisposed on a plane that contains the rear end 604 of the vehicle 600(e.g., rear end of trailer 614) and that is disposed orthogonally to thelengthwise axis 511 of the low drag low noise device 510. However, a lowdrag low noise device can be attached to another component, such as atrailer, or a first trailer and a second trailer, at any suitablelocation and angle. For example, a low drag low noise device can beattached to a component, such as a vehicle or trailer, such that thesecond end of the outer surface and/or the second end of the innersurface are not disposed on a plane that contains the rear end of thevehicle or trailer.

While the portion of the vehicle 600 on which the low drag low noisedevice 510 has been attached (e.g., trailer 614) has been illustrated ashaving a generally rectangular cross-sectional configuration and havinga substantially planar rear end, a vehicle or trailer can have anysuitable structural configuration and/or can form a portion of the outersurface of the inner body. For example, the vehicle or a trailer canform the inner body, such as those described herein, and the outer bodycan be attached to the inner body using any suitable structure, such asone or more connection fins. For example, a vehicle or trailer can havea cross-sectional configuration that is square, rectangular, elliptical,circular, oval, or any other shape considered suitable for a particularembodiment. For example, the rear end of a vehicle or trailer can beformed such that it is not substantially planar, such that it is curved,or forms any other suitable shape.

In the illustrated embodiment, the inner surface 532 of the outer body512 and the outer surface 542 of the inner body 514 cooperatively definea channel 554 within the passageway 534 defined by the outer body 512.The channel 554 extends along the entire length 527 of the outer body512 and is unobstructed along its length, except for the plurality ofconnection fins 518. The channel 554 has a first portion defined betweenthe outer body 512 and the vehicle 600 (e.g., trailer 614) and a secondportion defined between the outer body 512 and the inner body 514.However, alternative embodiments can include a channel that is entirelyformed between the inner surface of the outer body and the outer surfaceof the inner body, or between the inner surface of the outer body andthe outer surface of a vehicle, such as those described herein. Thechannel 554 has a first end 554′ and a second end 554″. The first end554′ of the channel 554 is disposed between the first end 538 of theinner body 514 and the second end 540 of the inner body 514. The secondend 554″ disposed between the first end 554′ and the second end 540 ofthe inner body 514. During use, fluid enters the channel 554 at thefirst end 554′ and exits the channel 554 at the second end 554″. In theillustrated embodiment, the channel 554 is defined about the entirecircumference of the vehicle (e.g., trailer 614), such that a firstportion is defined on the first side 606, a second portion is defined onthe second side 608, a third portion is defined on the roof 610, and afourth portion is defined on the undercarriage 612. Alternatively, achannel can be defined about a portion of the circumference of motorvehicle 600, such as a trailer (e.g., on one or more of the first side620, second side 622, roof 624, undercarriage 626).

As best illustrated in FIG. 30, the channel 554 has a firstcross-sectional area 556 disposed on a first plane 557 that is disposedorthogonal to the lengthwise axis 511 of the low drag low noise device510. The first plane 557 is disposed between the first end 538 and thesecond end 540 of the inner body 514. The channel 554 has a secondcross-sectional area 558 disposed on a second plane 559 that is disposedorthogonal to the lengthwise axis 511 of the low drag low noise device510. The second plane 559 is disposed between the first plane 557 andthe second end 540 of the inner body 514. The first cross-sectional area556 is greater than the second cross-sectional area 558. Thus, the innersurface 532 of the outer body 512 and the outer surface 542 of the innerbody 514 converge from the first end 538 of the inner body 514 to thesecond end 540 of the inner body 514. Optionally, the firstcross-sectional area 556 can be disposed at the first end 554′ of thechannel 554 and the second cross-sectional configuration 558 can bedisposed at the second end 554″ of the channel 554. By reducing thecross-sectional area of the channel 554 from the first end 538 of theinner body 514 to the second end 540 of the inner body 514, fluidaccelerates as it is passed through the channel 554 and exits the lowdrag low noise device 510 at a velocity that is greater than thevelocity at which it entered the low drag low noise device 510.

In the illustrated embodiment, the channel 554 has a first height at thefirst end 554″ of the channel 554 and a second height at the second end554″ of the channel 554. The first height is measured on an axis that isperpendicular to the lengthwise axis 511 of the low drag low noisedevice. The second height is measured on an axis that is perpendicularto the lengthwise axis 511 of the low drag low noise device 510. Thesecond height of the channel is equal to between about 0.01% and about5.0% of the first diameter 543 (e.g., width of trailer, diameter ofcomponent to which the low drag low noise device is attached, thecorresponding diameter) or the second diameter 543′ (e.g., height oftrailer, diameter of the component to which the low drag low noisedevice is attached, the corresponding diameter) of the second end 540 ofthe inner body 514. However, in embodiments in which the first diameterand/or the second diameter are different, or vary, alternativeembodiments can have a channel that has a second height that is equal tobetween about 0.01% and about 5.0% of the average height of the firstdiameter and/or the second diameter. The first height of the channel 554is equal to between about 1.1 times to about 10 times the value of thesecond height. However, alternative embodiments can include any suitablefirst height and/or second height for a channel, and skilled artisanswill be able to select a suitable height for a channel according to aparticular embodiment based on various considerations, including thedesired flow characteristics intended to be achieved. For example, asecond height of a channel can be equal to between about 0.1% and about2.0% of the first diameter 543 (e.g., width of trailer, diameter of thecomponent to which the low drag low noise device is attached, thecorresponding diameter) or the second diameter 543′ (e.g., height oftrailer, diameter of the component to which the low drag low noisedevice is attached, the corresponding diameter) of the second end 540 ofthe inner body 514. For example, the first height of the channel 554 canbe equal to between about 2 times to about 5 times the value of thesecond height.

The inner surface 532 of the outer body 512 and the outer surface 542 ofthe inner body 514 are configured to allow a fluid (e.g., air) to passthrough the channel 554 from the first end 522 of the outer body 512 tothe second end 524 of the outer body 512 such that the fluid exits thechannel 554 at the second end 524 of the outer body 512 at an angle 560.The angle 560 is directed toward the lengthwise axis 511 of the low draglow noise device 510 and away from the rear end 604 of the vehicle 600(e.g., rear end 618 of trailer 614). Alternatively, the angle 560 can bedirected toward an axis that is parallel to the freestream flow of fluidthrough which the low drag low noise device 510 is traveling and thatextends through a portion of the inner body 514 of the low drag lownoise device 510. Angle 560 is measured relative to an axis thatcontains the second end 524 of the outer body 512 and that is parallelto the lengthwise axis 511 of the low drag low noise device 510.Alternatively, the angle 560 can be measured relative to an axis thatcontains the second end 524 of the outer body 512 and that is parallelto the freestream flow of fluid through which the low drag low noisedevice 510 is traveling. While angle 560 has been illustrated asconstant about the circumference of the second end 540 of the inner body514, angle 560 can alternatively vary about the circumference of thesecond end 540 of inner body 514. For example, fluid can exit thechannel defined by a low drag low noise device at a first angle and asecond angle at the second end of channel. The first angle can bedifferent from, or the same as, the second angle and can comprise anysuitable angle, such as those described herein with respect to angle560.

During travel, the channel 554 directs the flow of fluid (e.g., air)through the low drag low noise device 510 to accomplish a reduction innoise and/or drag relative to a motor vehicle that does not include alow drag low noise device. During use, fluid enters the low drag lownoise device 510 through the first opening 528 of the outer body 512 andis directed through channel 554 between the outer body 512 and the innerbody 514 and exits through the second opening 530 defined by the outerbody 512 as a jet of fluid 564. The jet of fluid 564 travels at aspecific velocity and at angle 560. This is best shown in FIG. 30. Basedon angle 560, the noise level and/or drag is reduced as a result of jetof fluid 564 altering the base flow relative to a device that does notinclude a channel. In addition, as a result of the jet of fluid 564converging toward the lengthwise axis 511 of the low drag low noisedevice 510 a smooth virtual trailing edge, or boat-tail, is created.This smooth trailing edge, or boat-tail, prevents or reduces vortexshedding and increases base pressure relative to devices that do notinclude a channel, such as those illustrated in FIGS. 1 through 4. Byreducing vortex shedding and increasing the base pressure, the noiseand/or drag produced by the low drag low noise device 510 is reducedrelative to devices that do not include a channel, such as thoseillustrated in FIGS. 1 through 4.

The angle and velocity at which the jet of fluid 564 exits the channel554 will be based on a number of characteristics, such as the structuralarrangement of the outer surface 526 of the outer body 512, thestructural arrangement between the outer body 512 and the inner body 514at the first end 522 and second end 524 of the outer body 512, thestructural arrangement between the outer body 512 and the inner body 514along channel 554, the first cross-sectional area 556, and/or the secondcross-sectional area 558. It is to be understood that the abovecharacteristics of the low drag low noise device 510 may be modifiedwithin the scope of the present disclosure in the interest of obtainingthe optimum exit angle and velocity which results in the greatestreduction in noise and/or drag.

While the vehicle 600 has been illustrated as a semi-truck with anattached trailer 614, a low drag low noise device can be attached to anysuitable motor vehicle, or component attached to a motor vehicle, and atany suitable location on the motor vehicle or component, and skilledartisans will be able to select a suitable motor vehicle or component toattach a low drag low noise device according to a particular embodimentbased on various considerations, including the structural configurationof the motor vehicle or component. For example, a vehicle can compriseany motor vehicle, truck, semi-truck, pick-up truck, car, bus, SUV, van,locomotive, aircraft, flying object, airplane, projectile, rocket,missile, jet, ship, boat, and any other object that can travel through afluid, such as air.

FIG. 31 illustrates another low drag low noise device 710. Low drag lownoise device 710 is similar to the low drag low noise device 510illustrated in FIGS. 29 and 30 and described above, except as detailedbelow. Reference numbers in FIG. 31 refer to the same structural elementor feature referenced by the same number in FIGS. 29 and 30, offset by200. Thus, low drag low noise device 710 comprises an outer body 712, aninner body 714, and a plurality of connection fins 718.

In the illustrated embodiment, the low drag low noise device 710 isattached to the vehicle 800 (e.g., trailer 814) between its front endand rear end 804 such that the second end 724 of the outer body 712 andthe second end 740 of the inner body 714 are disposed beyond the rearend 804 of the vehicle 800 (e.g., rear end of the trailer 814). Thus,the rear end 804 of the vehicle 800 is disposed on a first plane that isdisposed orthogonal to the lengthwise axis 711 of the low drag low noisedevice 710 and that extends through the outer body 712 and the innerbody 714. The second end 724 of the outer body 712 is disposed on asecond plane that is disposed orthogonal to the lengthwise axis 711 ofthe low drag low noise device 710. The second end 740 of the inner body714 is disposed on a third plane that is disposed orthogonal to thelengthwise axis 711 of the low drag low noise device 710. The firstplane is disposed between the front end of the vehicle 800 and thesecond plane. The third plane is disposed between the first plane andthe second plane. Alternatively, the second plane and the third planecan be coplanar.

In the illustrated embodiment, the outer body 712 has a thickness 733that is constant along its length 727 and the inner body 714 has athickness 733′ that is constant along its length 741. The thickness 733of the outer body 712 is equal to the thickness 733′ of the inner body714. However, alternative embodiments can include an outer body that hasa thickness that is not equal to (e.g., greater than, less than) thethickness of the inner body. In addition, alternative embodiments caninclude an outer body and/or an inner body that has a thickness thatvaries along the length of the outer body and/or inner body.

In the illustrated embodiment, when the inner body 714 is attached toanother component, such as the vehicle 800, it creates a void 832between the inner surface 746 of the inner body 714 and the outersurface of the component to which the low drag low noise device 710 isattached (e.g., vehicle 800, trailer 814). However, alternativeembodiments can omit the inclusion of a void (e.g., void 832) by formingthe inner body as a portion of the component to which the outer body isattached (e.g., inner body is formed as part of the vehicle, inner bodyis formed as part of the trailer). In these alternative embodiments, theinner body comprises a portion of the vehicle (e.g., trailer).

FIG. 32 illustrates another low drag low noise device 910. Low drag lownoise device 910 is similar to the low drag low noise device 710illustrated in FIGS. 29 and 30 and described above, except as detailedbelow. Reference numbers in FIG. 32 refer to the same structural elementor feature referenced by the same number in FIGS. 29 and 30, offset by400. Thus, low drag low noise device 910 comprises an outer body 912, aninner body 914, and a plurality of connection fins 918.

In the illustrated embodiment, the outer body 912 has a thickness 933that is constant along its length 927 and the inner body 914 comprises aportion of the vehicle 1000 (e.g., a portion of trailer 1014). Thelength of the inner body 914 is greater than the length 927 of the outerbody 912. In the embodiment illustrated, the second end 924 of the outerbody 912 is disposed on a plane that is contains the rear end 1004 ofthe vehicle 1000 and that is disposed orthogonal to the lengthwise axis911 of the low drag low noise device 910. The inner body 914 has a firstportion that extends on an axis that is parallel to the lengthwise axis911 of the low drag low noise device 910 and a second portion that iscurved toward the lengthwise axis 911 of the low drag low noise device910. This structural configuration forms a converging channel 954, asdescribed herein, such that the fluid exits the channel 954 at thesecond end 924 of the outer body 912 at an angle 960.

While the second end 924 of the outer body 912 has been described asbeing disposed on a plane that contains the rear end of the vehicle 1000(e.g., rear end of trailer 1014) and that is disposed orthogonal to thelengthwise axis 911 of the low drag low noise device 910, the second endof an outer body can be positioned at any suitable location and at anysuitable angle. For example, the second end of an outer body can bepositioned on a plane that is disposed orthogonal to the lengthwise axisof the low drag low noise device and that is positioned between thefront end and the rear end, or beyond the rear end (e.g., downstream),of the component to which the low drag low noise device is attached.

FIGS. 33 and 34 illustrate another low drag low noise device 1110. Lowdrag low noise device 1110 is similar to the low drag low noise device710 illustrated in FIG. 31 and described above, except as detailedbelow. Reference numbers in FIGS. 33 and 34 refer to the same structuralelement or feature referenced by the same number in FIG. 31, offset by400. Thus, low drag low noise device 1110 comprises an outer body 1112,an inner body 1114, and a plurality of connection fins 1118.

FIG. 33 is a top view of a portion 1240 of the low drag low noise device1110 that is releasably attached to the roof of the vehicle 1200 (e.g.,trailer 1214). The portion 1240 comprises a first segment 1242, a secondsegment 1244, and a third segment 1246 and is moveable between a firstconfiguration and a second configuration. The first segment 1242 ishingedly attached to the second segment 1244 by first hinge 1248. Thesecond segment 1244 is hingedly attached to the third segment 1246 bysecond hinge 1250. Each of the first segment 1242, second segment 1244,and third segment 1246 is moveable between a first position and a secondposition, as described in more detail herein. While only a portion 1240of the low drag low noise device 1110 has been illustrated as formed ofa plurality of segments, the entirety, or a portion, of the low drag lownoise device 1110 can be formed of a plurality of segments, such asthose described.

The first segment 1242 is attached to the second segment 1244 using anysuitable type of hinged attachment. In the illustrated embodiment, thefirst hinge 1248 is a piano hinge. The second segment 1244 is attachedto the third segment 1246 using any suitable type of hinged attachment.In the illustrated embodiment, the second hinge 1250 is a piano hinge.Skilled artisans will be able to select a suitable type of hinge toattach a first segment to a second segment and to attach a secondsegment to a third segment according to a particular embodiment based onvarious considerations, such as that material(s) that forms eachsegment. Example hinges considered suitable include, but are not limitedto, strap hinges, tee hinges, butt hinges, offset hinges, swing-awayhinges, continuous hinges, piano hinges, living hinges, and any otherhinge considered suitable for a particular embodiment.

When each of the segments 1242, 1244, 1246 is in the first position, asillustrated in FIG. 33, the portion 1240 of the low drag low noisedevice 1110 is in the first configuration and the first segment 1242,the second segment 1244, and the third segment 1246 are disposed on aplane. In the first position, the first segment 1242 is fixed relativeto the second segment 1244 and the second segment is fixed relative tothe third segment 1246. Fixing the first segment 1242 to the secondsegment 1244 and the second segment 1244 to the third segment 1246 canbe accomplished using any suitable structure, including but not limitedto, fasteners, latches, compression latches, pull action latches, usingthreaded connections, and any other structures considered suitable for aparticular embodiment.

When each of the segments 1242, 1244, 1246 is in the second position, asillustrated in FIG. 34, the portion 1240 of the low drag low noisedevice 1110 is in the second configuration and the first segment 1242 isdisposed parallel to the second segment 1244 and the second segment 1244is disposed parallel to the third segment 1246. Movement of the segments1242, 1244, 1246 between their respective first positions and secondpositions provides a mechanism for moving the low drag low noise device1110 between its first configuration and second configuration. In thefirst configuration, the low drag low noise device 1110 is assembled andconfigured for use. In the second configuration, the low drag low noisedevice 1110 is collapsed on itself such that it can be shipped or movedfrom a first location to a second location.

The low drag low noise device 1110 can be releasably attached to themotor vehicle 1200 (e.g., trailer 1214) using any suitable method ortechnique, and skilled artisans will be able to select a suitable methodor technique to attach a low drag low noise device to another component,such as a trailer or motor vehicle, according to a particular embodimentbased on various considerations, including the material(s) that formsthe component and/or the low drag low noise device. Example methods andtechniques considered suitable to attach a low drag low noise device toanother component, such as a trailer or a motor vehicle, include usingone or more straps, threaded components (e.g., screws, nuts, bolts),defining a flange on a portion or the entirety of the inner body that issized and configured to be received by a slot or recess defined by thecomponent, and any other method or technique considered suitable for aparticular embodiment.

While the portion 1240 of the low drag low noise device 1110 has beenillustrated as having a first segment 1242, a second segment 1244, and athird segment 1246, a low drag low noise device, or a portion of a lowdrag low noise device, can have any suitable number of segments that aremoveably, hingedly, or releasably attached to one another. Skilledartisans will be able to select a suitable number of segments to form alow drag low noise device according to a particular embodiment based onvarious considerations, including the circumference of the low drag lownoise device. Example number of segments considered suitable to form alow drag low noise device, or a portion of a low drag low noise device,include one, at least one, two, a plurality, three, four, five, six, andany other number of segments considered suitable for a particularembodiment.

While the segments 1242, 1244, 1246 have been illustrated as hingedlyattached to one another, the segments of a low drag low noise device canalternatively be releasably attached to one another when in the firstposition such that that they can be detached from one another to bepositioned in the second position. Releasable attachment can beaccomplished using any suitable structure, such as hinges, compressionhinges, snap fit configurations, tongue and groove configurations,sliding lock configurations, those described herein, and any otherstructure, method, or technique considered suitable for a particularembodiment.

FIGS. 35, 36 and 37 illustrate another low drag low noise device 1310.Low drag low noise device 1310 is similar to the low drag low noisedevice 910 illustrated in FIG. 32 and described above, except asdetailed below. Reference numbers in FIGS. 35, 36, and 37 refer to thesame structural element or feature referenced by the same number in FIG.32, offset by 400. Thus, low drag low noise device 1310 comprises anouter body 1312, an inner body 1314, and a plurality of connection fins1318.

In the illustrated embodiment, the inner body 1314 comprises a portionof the component on which the outer body 1312 is attached using theplurality of connection fins 1318. In the embodiment illustrated, thecomponent is a vehicle 1400 (e.g., a car).

The outer body 1312 extends around the entire circumference of the innerbody 1314 and forms the channel 1354 between the inner surface 1332 ofthe outer body 1312 and the outer surface 1342 of the inner body 1314.While the outer body 1312 has been illustrated as being disposed aroundthe entire circumference of the inner body 1314, alternative embodimentscan include an outer body that extends around a portion of thecircumference of the inner body.

FIG. 38 illustrates another low drag low noise device 1510. Low drag lownoise device 1510 is similar to the low drag low noise device 1310illustrated in FIGS. 35, 36, and 37 and described above, except asdetailed below. Reference numbers in FIG. 38 refer to the samestructural element or feature referenced by the same number in FIGS. 35,36, and 37, offset by 200. Thus, low drag low noise device 1510comprises an outer body 1512, an inner body 1514, and a plurality ofconnection fins 1518.

In the illustrated embodiment, the inner body 1514 defines a convexportion 1664 that extends away from the lengthwise axis 1511 of the lowdrag low noise device 1510. The convex portion 1664 is disposed betweenthe first end 1522 and the second end 1524 of the outer body 1512 andextends into the passageway 1554. This structural arrangement forms thechannel 1554 that converges from the first end 1522 of the outer body1512 to the second end 1524 of the outer body 1512. The convex portion1664 extends around the entire circumference of the vehicle 1600.However, alternative embodiments can include a convex portion thatextends around a portion of the circumference of the vehicle.

FIGS. 39 and 40 illustrate a first low drag low noise device 1710 and asecond low drag low noise device 1910 attached to a vehicle 1800. Thefirst low drag low noise device 1710 is similar to the low drag lownoise device 1310 illustrated in FIGS. 35, 36, and 37 and describedabove, except as detailed below. The second low drag low noise device1910 is similar to the low drag low noise device 510 illustrated inFIGS. 29 and 30. With respect to the first low drag low noise device1710, reference numbers in FIGS. 39 and 40 refer to the same structuralelement or feature referenced by the same number in FIGS. 35, 36, and37, offset by 400. With respect to the second low drag low noise device1910, reference numbers in FIGS. 39 and 40 refer to the same structuralelement or feature referenced by the same number in FIGS. 29 and 30,offset by 1400. Thus, the first low drag low noise device 1710 comprisesan outer body 1712, an inner body 1714, and a plurality of connectionfins 1718 and the second low drag low noise device 1910 comprises anouter body 1912, an inner body 1914, and a plurality of connection fins1918.

In the illustrated embodiment, the first low drag low noise device 1710is attached between the front end 1802 and the rear end 1804 of thevehicle 1800 and extends around a portion of the circumference of theinner body 1714 (e.g., the roof, the first side, the second side). Theinner body of the first low drag low noise device 1710 comprises aportion of the vehicle 1800. While the first low drag low noise device1710 has been illustrated as extending around a portion of thecircumference of the inner body 1714, a low drag low noise device canextend around any suitable portion of the circumference of an innerbody, or a vehicle. For example, a low drag low noise device can extendaround the circumference of an inner body, or a vehicle, such that isforms a closed circumference, or extends around a partial circumferenceof the inner body, or vehicle.

In the illustrated embodiment, the second low drag low noise device 1910is attached between the first low drag low noise device 1710 and therear end 1804 of the vehicle 1800. The second low drag low noise device1910 is attached to the vehicle 1800 and extends around the entirecircumference of the vehicle 1800. The second end 1924 of the outer body1912 and the second end 1940 of the inner body 1914 are disposed on aplane that contains a portion, or the entirety, of the base surface 2066of the vehicle 1800. In the embodiment illustrated, the base surface2066 is the rear surface 2068 of a tailgate 2070. The low drag low noisedevice 1910 can optionally define a first slot and a second slot along aportion of the low drag low noise device that provide a mechanism toopen and close the tailgate 2070 in a conventional manner. While thetailgate 2070 has been illustrated as the base surface 2066, any othersurface of a motor vehicle, or a component attached to a motor vehicle(e.g., a trailer, side view mirror) can form the base surface. While thesecond low drag low noise device 1910 has been illustrated as extendingaround the entire circumference of the vehicle 1800, a low drag lownoise device can extend around any suitable portion of the circumferenceof a vehicle. For example, a low drag low noise device can extend aroundthe circumference of a vehicle such that is forms a closedcircumference, or extends around a portion of the circumference of thevehicle (e.g., in embodiments in which a low drag low noise device isattached to a vehicle without a tailgate).

While the second low drag low noise device has been illustrated as aseparate component attached to a vehicle, a low drag low noise devicecan be formed as part of a vehicle. For example, the inner body cancomprise the outer surface of the vehicle and the outer body can beattached to the inner body using one or more connection fins.

FIG. 41 illustrates another low drag low noise device 2110. Low drag lownoise device 2110 is similar to the low drag low noise device 1910illustrated in FIGS. 39 and 40 and described above, except as detailedbelow. Reference numbers in FIG. 41 refer to the same structural elementor feature referenced by the same number in FIGS. 39 and 40, offset by200. Thus, low drag low noise device 2110 comprises an outer body 2112,an inner body 2114, and a plurality of connection fins 2118.

In the illustrated embodiment, a portion, or the entirety, of the basesurface 2266 of the vehicle 2200 is disposed on a first plane, thesecond end 2124 of the outer body 2112 is disposed on a second plane,and the second end 2140 of the inner body 2112 is disposed on a thirdplane. The first plane is disposed between the front end of the vehicleand the second plane. The second plane is coplanar with the third plane.However, alternative embodiments can include a second plane that is notcoplanar with a third plane (e.g., second plane is disposed between thefirst plane and the third plane).

FIG. 42 illustrates another low drag low noise device 2310. Low drag lownoise device 2310 is similar to the low drag low noise device 1910illustrated in FIGS. 39 and 40 and described above, except as detailedbelow. Reference numbers in FIG. 42 refer to the same structural elementor feature referenced by the same number in FIGS. 39 and 40, offset by400. Thus, low drag low noise device 2310 comprises an outer body 2312,an inner body 2314, and a plurality of connection fins 2318.

In the illustrated embodiment, the tailgate 2470 has a rear surface 2468and a front surface 2472 and the low drag low noise device 2310 has aconfiguration as described below. The first end 2322 of the outer body2312 is disposed on a first plane. The second end 2324 of the outer body2312 is disposed on a second plane. The first end 2338 of the inner body2314 is disposed on a third plane. The second end 2340 of the inner body2314 is disposed on a fourth plane. The front surface 2472 of thetailgate 2470 is disposed on a fifth plane. The rear surface 2468 of thetailgate 2470 is disposed on a sixth plane. The first plane is disposedbetween the front end of the vehicle 2400 and the tailgate 2470. Thesecond plane is coplanar with the fourth plane and the sixth plane. Thethird plane is disposed between the first plane and the second plane andis coplanar with the fifth plane.

FIG. 43 illustrates another low drag low noise device 2510. Low drag lownoise device 2510 is similar to the low drag low noise device 1910illustrated in FIGS. 39 and 40 and described above, except as detailedbelow. Reference numbers in FIG. 43 refer to the same structural elementor feature referenced by the same number in FIGS. 39 and 40, offset by600. Thus, low drag low noise device 2510 comprises an outer body 2512,an inner body 2514, and a plurality of connection fins 2518.

In the illustrated embodiment, the second end 2524 of the outer body2512 defines a sinusoidal edge 2584 and the outer surface 2526 has awaved configuration that corresponds to the to the sinusoidal edge 2584.Sinusoidal edge 2584 is defined along a plane that is orthogonal to thelengthwise axis 2511 of the low drag low noise device 2510. Thesinusoidal edge 2584 comprises a plurality of peaks 2586 and troughs2588 and can comprise any suitable amplitude and frequency. Thisstructural arrangement provides a mechanism for enhancing the mixture offluid that passes over the outer surface 2526 of the outer body 2512 andthat travels through passageway 2554.

While the second end 2524 of the outer body 2512 has been described ashaving a sinusoidal edge 2584, the second end of the outer body of a lowdrag low noise device can define any suitable structural configuration.Skilled artisans will be able to select a suitable structuralconfiguration for the second end of an outer body according to aparticular embodiment based on various considerations, including theflow characteristics intended to be achieved. Example structuralconfigurations considered suitable include curved, wavy, angled,sinusoidal, and any other structural configuration considered suitablefor a particular embodiment.

While the second end 2524 of the outer body 2512 and a portion of theouter surface 2526 of the outer body 2512 have been illustrated ashaving a particular structural arrangement, the outer body of a low draglow noise device can have any suitable structural arrangement. Skilledartisans will be able to select a suitable structural arrangement forthe outer body of a low drag low noise device according to a particularembodiment based on various considerations, including the flowcharacteristics intended to be achieved. Alternative to defining asinusoidal edge that is defined on a plane that is orthogonal to thelengthwise axis of a low drag low noise device, a sinusoidal edge can bedefined as described with respect to FIGS. 26, 27, and 28.

The first end 2554′ and second end 2554″ of channel 2554 can compriseany suitable cross-sectional area, and skilled artisans will be able toselect a suitable cross-sectional area for the first end and second endof a channel according to a particular embodiment based on variousconsiderations, including the desired flow characteristics intended tobe achieved at the first end and/or second end of the channel. Exampleratios considered suitable between a first cross-sectional area at thefirst end of a channel (e.g., disposed on a first plane that isorthogonal to the lengthwise axis of a low drag low noise device) and asecond cross-sectional area at the second end of a channel (e.g.,disposed on a second plane that is orthogonal to the lengthwise axis ofthe low drag low noise device and parallel to the first plane) includeratios equal to 1.0, equal to about 1.0, equal to 1.1, equal to about1.1, equal to 2.0, equal to about 2.0, equal to 3.0, equal to about 3.0,equal to 8.0, equal to about 8.0, equal to 10.0, equal to about 10.0,equal to between 1.0 and 10, and equal to between about 1.0 and about10.

The foregoing detailed description provides exemplary embodiments of theinvention and includes the best mode for achieving a low drag low noisedevice. The description and illustration of these embodiments isintended only to provide examples of the invention, and not to limit thescope of the invention, or its protection, in any manner. It is to beunderstood that modifications and variations can be made to theembodiments described herein without departing from the spirit and scopeof the disclosure.

What is claimed is:
 1. A low drag low noise device for use on a vehiclehaving a front end, a rear end, and a circumference, the low drag lownoise device having a lengthwise axis and comprising: an outer bodyhaving a first end and a second end, the outer body defining a firstopening, a second opening, and an inner surface, the inner surfaceextending from the first opening to the second opening and defining apassageway; and an inner body attached to said vehicle and to the outerbody, the inner body at least partially disposed within the passagewaydefined by the outer body, the inner body having a first end, a secondend, an inner surface, and an outer surface; wherein the inner surfaceof the outer body and the outer surface of the inner body define achannel within the passageway of the outer body, the channel having afirst cross-sectional area disposed on a first plane and a secondcross-sectional area disposed on a second plane, the first planedisposed orthogonal to said lengthwise axis of said low drag low noisedevice, the first plane disposed between the first end of the inner bodyand the second end of the inner body, the second plane disposedorthogonal to said lengthwise axis of said low drag low noise device,the second plane disposed between the first plane and the second end ofthe inner body, the first cross-sectional area being greater than thesecond cross-sectional area such that the channel converges from thefirst end of the inner body to the second end of the inner body, thechannel configured to allow a fluid to pass through the channel from thefirst end of the outer body to the second end of the outer body suchthat the fluid exits the channel at the second end of the outer body atan angle that is directed toward said lengthwise axis of said low draglow noise device and away from the second end of the inner body.
 2. Thelow drag low noise device of claim 1, wherein the channel is definedabout the entire circumference of said vehicle.
 3. The low drag lownoise device of claim 1, wherein the inner surface of the inner body hasa diameter; wherein the channel has a first end and a second end, thechannel having a first height at the first end of the channel that ismeasured on an axis that is perpendicular to said lengthwise axis ofsaid low drag low noise device, the channel having a second height atthe second end of the channel that is measured on an axis that isperpendicular to said lengthwise axis of said low drag low noise device;wherein the first height of the channel is equal to between about 1.1 toabout 10 times the second height; and wherein the second height is equalto between about 0.01% and about 5.0% of the diameter of the innersurface of the inner body.
 4. The low drag low noise device of claim 1,wherein the inner surface of the inner body has a diameter; wherein thechannel has a first end and a second end, the channel having a firstheight at the first end of the channel that is measured on an axis thatis perpendicular to said lengthwise axis of said low drag low noisedevice, the channel having a second height at the second end of thechannel that is measured on an axis that is perpendicular to saidlengthwise axis of said low drag low noise device; wherein the firstheight of the channel is equal to between about 2 to about 5 times thesecond height; and wherein the second height is equal to between about0.1% and about 2.0% of the diameter of the inner surface of the innerbody.
 5. The low drag low noise device of claim 1, wherein the angle isbetween about 0 degrees and about 50 degrees relative to an axis thatcontains the second end of the outer body and that is parallel to saidlengthwise axis of said low drag low noise device.
 6. The low drag lownoise device of claim 1, wherein the outer surface of the inner body hasan outer surface section that extends from a first end to a second end,the first end of the outer surface section is disposed between the firstend and the second end of the inner body, the second end of the outersurface section is disposed between the first end of the outer surfacesection and the second end of the inner body, the outer surface sectionextending toward said lengthwise axis of said low drag low noise devicefrom the first end of the outer surface section to the second end of theouter surface section at angle between about 0 degrees and about 50degrees relative to an axis that contains the second end of the outerbody and that is parallel to said lengthwise axis of said low drag lownoise device.
 7. The low drag low noise device of claim 1, wherein theouter body has a length that extends from the first end of the outerbody to the second end of the outer body; wherein the inner body has alength that extends from the first end of the inner body to the secondend of the inner body; and wherein the length of the inner body isdifferent than the length of the outer body.
 8. The low drag low noisedevice of claim 7, wherein the length of the inner body is greater thanthe length of the outer body; and wherein the first end of the innerbody is disposed outside of the passageway defined by the outer body. 9.The low drag low noise device of claim 1, wherein said rear end of saidvehicle is disposed on a third plane that is orthogonal to saidlengthwise axis of said low drag low noise device, the third planeextending through the outer body and the inner body; wherein the secondend of the outer body is disposed on a fourth plane that is orthogonalto said lengthwise axis of said low drag low noise device; wherein thesecond end of the inner body is disposed on a fifth plane that isorthogonal to said lengthwise axis of said low drag low noise device;wherein the third plane is disposed between said front end of saidvehicle and the fourth plane; and wherein the fifth plane is disposedbetween the third plane and the fourth plane.
 10. The low drag low noisedevice of claim 1, wherein said rear end of said vehicle is disposed ona third plane that is orthogonal to said lengthwise axis of said lowdrag low noise device; wherein the second end of the outer body isdisposed on a fourth plane that is orthogonal to said lengthwise axis ofsaid low drag low noise device; and wherein the third plane is coplanarwith the fourth plane.
 11. The low drag low noise device of claim 1,wherein the second end of the outer body defines a sinusoidal edge. 12.A low drag low noise device for use on a vehicle having a front end, arear end, and a circumference, the low drag low noise device having alengthwise axis and comprising: an outer body having a first end, asecond end, and a length extending from the first end of the outer bodyto the second end of the outer body, the outer body defining a firstopening, a second opening, and an inner surface, the inner surfaceextending from the first opening to the second opening and defining apassageway; and an inner body attached to said vehicle and to the outerbody, the inner body at least partially disposed within the passagewaydefined by the outer body, the inner body having a first end, a secondend, an inner surface, an outer surface, and a length extending from thefirst end of the inner body to the second end of the inner body, thelength of the inner body being different than the length of the outerbody; wherein the inner surface of the outer body and the outer surfaceof the inner body define a channel within the passageway of the outerbody, the channel defined about the entire circumference of saidvehicle, the channel having a first cross-sectional area disposed on afirst plane and a second cross-sectional are disposed on a second plane,the first plane disposed orthogonal to said lengthwise axis of said lowdrag low noise device, the first plane disposed between the first end ofthe inner body and the second end of the inner body, the second planedisposed orthogonal to said lengthwise axis of said low drag low noisedevice, the second plane disposed between the first plane and the secondend of the inner body, the first cross-sectional area being greater thanthe second cross-sectional area such that the channel converges from thefirst end of the inner body to the second end of the inner body, thechannel configured to allow a fluid to pass through the channel from thefirst end of the outer body to the second end of the outer body suchthat the fluid exits the channel at the second end of the outer body atan angle that is directed toward said lengthwise axis of said low draglow noise device and away from the second end of the inner body, theangle being between about 0 degrees and about 50 degrees relative to anaxis that contains the second end of the outer body and that is parallelto said lengthwise axis of said low drag low noise device.
 13. The lowdrag low noise device of claim 12, wherein the inner surface of theinner body has a diameter; wherein the channel has a first end and asecond end, the channel having a first height at the first end of thechannel that is measured on an axis that is perpendicular to saidlengthwise axis of said low drag low noise device, the channel having asecond height at the second end of the channel that is measured on anaxis that is perpendicular to said lengthwise axis of said low drag lownoise device; wherein the first height of the channel is equal tobetween about 1.1 to about 10 times the second height; and wherein thesecond height is equal to between about 0.01% and about 5.0% of thediameter of the inner surface of the inner body.
 14. The low drag lownoise device of claim 12, wherein the inner surface of the inner bodyhas a diameter; wherein the channel has a first end and a second end,the channel having a first height at the first end of the channel thatis measured on an axis that is perpendicular to said lengthwise axis ofsaid low drag low noise device, the channel having a second height atthe second end of the channel that is measured on an axis that isperpendicular to said lengthwise axis of said low drag low noise device;wherein the first height of the channel is equal to between about 2 toabout 5 times the second height; and wherein the second height is equalto between about 0.1% and about 2.0% of the diameter of the innersurface of the inner body.
 15. The low drag low noise device of claim12, wherein the outer surface of the inner body has an outer surfacesection that extends from a first end to a second end, the first end ofthe outer surface section is disposed between the first end and thesecond end of the inner body, the second end of the outer surfacesection is disposed between the first end of the outer surface sectionand the second end of the inner body, the outer surface sectionextending toward said lengthwise axis of said low drag low noise devicefrom the first end of the outer surface section to the second end of theouter surface section at angle between about 0 degrees and about 50degrees relative to an axis that contains the second end of the outerbody and that is parallel to said lengthwise axis of said low drag lownoise device.
 16. The low drag low noise device of claim 12, wherein thelength of the inner body is greater than the length of the outer body;and wherein the first end of the inner body is disposed outside of thepassageway defined by the outer body.
 17. The low drag low noise deviceof claim 12, wherein said rear end of said vehicle is disposed on athird plane that is orthogonal to said lengthwise axis of said low draglow noise device, the third plane extending through the outer body andthe inner body; wherein the second end of the outer body is disposed ona fourth plane that is orthogonal to said lengthwise axis of said lowdrag low noise device; wherein the second end of the inner body isdisposed on a fifth plane that is orthogonal to said lengthwise axis ofsaid low drag low noise device; wherein the third plane is disposedbetween said front end of said vehicle and the fourth plane; and whereinthe fifth plane is disposed between the third plane and the fourthplane.
 18. The low drag low noise device of claim 12, wherein said rearend of said vehicle is disposed on a third plane that is orthogonal tosaid lengthwise axis of said low drag low noise device; wherein thesecond end of the outer body is disposed on a fourth plane that isorthogonal to said lengthwise axis of said low drag low noise device;and wherein the third plane is coplanar with the fourth plane.
 19. Thelow drag low noise device of claim 12, wherein the second end of theouter body defines a sinusoidal edge.
 20. A low drag low noise devicefor use on a vehicle having a front end, a rear end, and acircumference, the low drag low noise device having a lengthwise axisand comprising: an outer body having a first end, a second end, and alength extending from the first end of the outer body to the second endof the outer body, the outer body defining a first opening, a secondopening, and an inner surface, the inner surface extending from thefirst opening to the second opening and defining a passageway; and aninner body attached to said vehicle and to the outer body, the innerbody at least partially disposed within the passageway defined by theouter body, the inner body having a first end, a second end, an innersurface, an outer surface, and a length extending from the first end ofthe inner body to the second end of the inner body, the inner surface ofthe inner body having a diameter, the length of the inner body beingdifferent than the length of the outer body; wherein the inner surfaceof the outer body and the outer surface of the inner body define achannel within the passageway of the outer body, the channel definedabout the entire circumference of said vehicle, the channel having afirst cross-sectional area disposed on a first plane, a secondcross-sectional area disposed on a second plane, a first end, a secondend, a first height, and a second height, the first plane disposedorthogonal to said lengthwise axis of said low drag low noise device,the first plane disposed between the first end of the inner body and thesecond end of the inner body, the second plane disposed orthogonal tosaid lengthwise axis of said low drag low noise device, the second planedisposed between the first plane and the second end of the inner body,the first cross-sectional area being greater than the secondcross-sectional area such that the channel converges from the first endof the inner body to the second end of the inner body, the channelconfigured to allow a fluid to pass through the channel from the firstend of the outer body to the second end of the outer body such that thefluid exits the channel at the second end of the outer body at an anglethat is directed toward said lengthwise axis of said low drag low noisedevice and away from the second end of the inner body, the angle beingbetween about 0 degrees and about 50 degrees relative to an axis thatcontains the second end of the outer body and that is parallel to saidlengthwise axis of said low drag low noise device, the first heightdisposed at the first end of the channel, the first height measured onan axis that is perpendicular to said lengthwise axis of said low draglow noise device, the second height disposed at the second end of thechannel, the second height measured on an axis that is perpendicular tosaid lengthwise axis of said low drag low noise device, the first heightof the channel being equal to between about 1.1 to about 10 times thesecond height, the second height being equal to between about 0.01% andabout 5.0% of the diameter of the inner surface of the inner body.